Expanding boring-head and screwing-head.



J. W. BRADLEY.

EXPANDING BORING HEAD AND SCREWING HEAD.

APPLICATION FILED APR-11,1913- Patented Mar. 28,1916.

3 SHEETS-SHEET I I IVE/Eyre)? JUN/Y WILLIAM .BRHDLEY Ma 5. fi/aZafi A TTOR'NE I.

WIT/VE'SSES E THE COLUMBIA PLANOGRAPH C0,, WASHINGTON. D. c.

J. W. BRADLEY.

EXPANDING BORING HEAD AND SCREWING HEAD.

Patented Mar. 28, 1916.

3 SHEETSSHEET2.

APPLICATION FILED APR. 1|, m3. 1,1?6512;

INVEIYT'OR JOHN WILLIAM BR/LDLEY. 1 Efi%mZ/(/Qjld; flTTOR/VEY :IU I... 1111 ll a I H MWHIW E E. v H E M in- 1| N HMMI I WI H E. W B G -Ejfiljl EX @m? w P b WITNESSES J. W. BRADLEY.

.EXPANDING BORING HEAD AND SCREWING HEAD.

APPLICATION FILED APR. H, 1913.

Patented Mar. 28, 1916.

3 SHEETS-SHEET 3.

JJ m: :m7%

VflT/V'ESSES ms COLUMBIA PLANuuRAPn cm, WASHXNGTON, D. c.

JOHN WILLIAM BRA-DLEYLOF LEEDS, ENGLAND.

EXPANDING BORING-HEAD AND sCREWING-HEAD.

Specification of Letters Patent.

Patented Mar. as, 1916.

Application filed April 11, 1913. Serial No. 760,532.

To all whom it may concern Be it known that I, J OHN WILLIAM BRAD- LEY, a subject of the King of Great Britain a and Ireland, residing at Leeds, in the county of York, England, have invented new and useful Improvements in Expanding Boring- Heads and screwing-Heads, of which the following is a specification.

This invention relates to an expanding and collapsing boring head and internal screwing head, the object of my present improvement being to provide for a minute adjustment of the cutters or dies and to insure anaccu'rate working of the same with a minimum 'of wear.

My present invention consists essentially in the application of a floating or rotating cam center to each slidingjaw, in conjunction with a micrometer adjustment device applied to the locking plunger.

Description of drawings-Figure 1 is an end elevation of an expanding and collapsing boring and screwing head having my present improvements applied. Fig. 2

is asectional 'sideelevation of Fig. 1. Fig. 3 is an end elevation, Fig. 4 a side elevation, and Fig. 5 a plan, ofsliding jaw fitted with the floating cam center. Fig. 6 is an end elevation, and Fig. 7 a side elevation, of sliding jaw fitted with a slightly modified form of floating cam center. Fig. 8 is an end elevation, and Fig. 9 is a sectional side elevation of recessed annular cam plate for same. Fig. 10 is an end elevation. Fig. 11 a side elevation, and Fig. 12 a plan, of sliding jaw fitted with a further modified form of floating cam center. Fig. 13 is an end elevation, and Fig. 14 a sectional side elevation, of recessed annular cam plate forsame.

The same letters of reference are employed throughout the specification and drawings to indicate corresponding parts.

According to my invention, tools or dies A are carried in jaws B which are slidably fitted in corresponding external recesses or pockets within the main body C of the head. A series of sliding jaws B are adjustable radially within the recesses or pockets by means of an intermediate cam plate F havinga series of cam rises or recesses'G which are adapted to'engage with recesses or protrusions in or from the sliding jaws B. The said cam plate F is held up to the sliding jaws B by means of an'outer disk or plate H fitting on a projecting boss from the main body, this outer disk or plate H being locked against a shoulder by means of an annular check nut or the like. This outer disk or plate H has an internal circumferential recess extending a considerable distance around that face abutting the plate F within which recess is fitted a cylindrical tension spring, one end of Which is secured to the cam plate F and the other to the disk H.

It maybe mentioned that the disk H is locked in position-on the cutter head while the cam plate F is normally free to revolve. The outer disk or plate H is provided also with a circumferential slot 0 of suitable length having a recess on its inner face and within this slot 0 is fitted a sliding block Q, having a corresponding inner shoulder adapted to engage with the said recess. This is particularly illustrated in Fig. 2. This sliding block Q carries a cylindrical plunger box S within which is fitted a spring plunger pin T adapted to engage with a hole U in the face of the intermediate cam plate F. The outer end of the plunger box S is fitted with a nut V for locking the sliding block Q, and its plunger box S within the circumferential slot 0.

One of the principal features of my present invention is a micrometer adjustment to be applied to this spring pressed plunger device which slides in the circumferential slot 0 of the outer disk or plate H. Thecylindrical plunger box S is carried in an elongated or slotted bearing 9 formedin a rotatable ring h which is recessed into the face of the outer disk or plate H, and is secured therein by means of T bolts 6 work ing within a T-shaped circumferential recess j. The rotatable ring it has a pair of projecting lugs 7c and Z, one on each sideof the plunger device, one lug k carrying a micrometer screw on of any suitable type (graduated preferably in thousandths of an inch or according to the metric scale) and the other lug Z carrying a suitable locking screw it the micrometer screw m and the locking screw n abutting on opposite sides against a collar O interposed between the plunger locking nut V and the outer disk or plate H.

In adjusting the cutters or dies A, the T bolts and the plunger locking nut V are slackened and the ring it carrying the plunger device is rotated to obtain first an approximate adjustment of the plunger device, the sliding block Q being held up to the faces of its slot 0 during this movement by means of an auxiliary spring 7). The T bolts 71 are then tightened, locking the ring it securely in position. The final adjustment of the plunger device is then obtained by' sliding the plunger device along its slotted bearing 9 in the ring it by means of the micrometer screw m, in which adjusted position it is locked by means of the plunger locking nut V and the locking screw a. The annular cam plate F is then rotated in the usual manner for engagement of its register hole U with the plunger pin T to determine the cutting position.

The recess a in which each projecting cam G engages to radially adjust its respective sliding jaw B within its external pocket, is formed (see Figs. 1 to 5) in a floating or rotating cam center I) mounted in the sliding jaw B, this arrangement being designed so that the recess a will conform to the cam rises G in any position of the annular cam plate F, thus overcoming the difficulty due to the center of rotation of the cam plate F not coinciding with the centers of curvature of the cam rises G. The necessity for play or looseness in the recess a (in a radial direction) is thus obviated, so that the recess a can be made a perfect sliding fit upon the cam rise and the recess, thus insuring absolute and permanent accuracy in the radial adjustment of the series of sliding jaws B carrying the cutters or dies A with a minimum ofwear.

In some cases the floating or rotating cam center 6, instead of having the recess a engaging the projecting cam rise Gr,'is formed with like effect (see Figs. 6 to 9) with a projection c integral therewith and engaging within a correspondingly recessed cam path cl in the annular cam plate F. Or the floating or rotating cam center 6 may have a larger projection 6 (see Figs. 10 to 14) mounted loosely thereon and in engagement with a correspondingly recessed cam path f in the annular cam plate F.

In adjusting the cutters or dies A, the plunger pin T is withdrawn clear of the cam plate F, the T bolts i and the plunger looking nut V are slackened, and the ring it carrying the plunger device and index finger is rotated to obtain first an approximate adjustment of the plunger device by means of the graduated scale on the outer disk or plate H, the sliding block Q being held up to the face of its slot 0, during this movement (to facilitate easy sliding) by means of an auxiliary spring 79. The T bolts '5 are then tightened, locking the ring 72, securely in position. If after trial a further fine adjustment of one or more thousandths of an inch (plus or minus) is required, this final and known adjustment of the plunger device is then obtained by easing the screw n and sliding the plunger device in the direction desired along its slotted bearing 9 in the rotatable ring it (now locked) by means ofthe micrometer screw m with its known graduations, in which adjusted position it 1s locked by meansof the plunger locking nut V and the locking screw n. The annular cam plate F is then rotated in the usual manner for'engagement of its register hole U with the plunger pin T to determine the cutting position. I

I claim:

1. In an'expanding' and collapsing boring and internal screwing head,.in combination, a rotatable annular cam plate'havlng pro ecting cam rises thereon, radially slidable jaws,

secured therein, shoes pivotally secured to.

said jaws having heads formedintegral and adapted to slidably engage in said cam re- ,cesses, a plunger co-acting with the annular 7 cam plate, means for normally pressing the plunger into engagement with the cam plate,

a locking screw adapted to engage the plunger and a mlcrometer ad usting means d1a metrically opposite the locking screw de-' signed to engage the plunger.

3. In an expanding and collapsing boring and internal screw threading head, in come bination, a rotatable cam plate, having an orifice therein, radially slidable tool holding jaws adapted to be engaged by said cam plate, spring means for rotating said cam plate, a head having a concentric slot and an annular recess in the rear thereof, a springplunger adjustably secured in said slot and having a pin adapted to engage the orifice in said cam plate, a ring having an opening adapted to provide clearance for said spring plunger and to be clamped in any desired position in said annular recess, brackets secured on diametrically opposite sides of the opening in said ring, a micrometer adjustment device secured to one of said brackets adapted to regulate the movement of said plunger boX, a pointer on said plunger box adapted to cooperate with a graduated scale on the rear of said head and with said micrometer device, and a locking screw making threaded engagement with the other bracket, substantially as described. 7

JOHN WVILLIAM BRADLEY.

Witnesses: v JOHN E. WALSH, ALLAN BENNETT.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of ratents Washington, D. G. 

